tevatron results on b-hadron lifetimes and rare decays...march 10-18, 2007 alberto...
TRANSCRIPT
-
XLII nd Rencontres de MORIONDElectroweak session, La Thuile,
March 10-18, 2007
Alberto Sánchez-HernándezCINVESTAV - Mexico City
On Behalf of the CDF and DØ Collaborations
Tevatron Results on b-hadronlifetimes and rare decays
-
March 10-18, 2007 Alberto Sánchez-Hernández XLII Moriond EW 2
B Physics at Tevatron
Lifetime and Rare Decays
τ(Bs) in Bs→J/ψφ, Bs→µνDsXτ(Λb) in Λb →µνΛc, Λb → J/ψ Λτ(Β0) in Β0 → J/ψ Κ0s, Β0 → J/ψ Κ∗0
τ(Β+) in Β+ → J/ψ Κ+
Limit on Bs→µµObservation of Bs→ψ(2S)φ, Bs→φφObservation of Bs→Ds1(2536)µν
I will show the first 2fb-1 result from the Tevatron
-
March 10-18, 2007 Alberto Sánchez-Hernández XLII Moriond EW 3
Tracking: Si, Sci-Fi & SolenoidU-LAr Cal
Muon Syst & Toroidsshielding
Important at the Tevatron• Triggering• Muons• Tracking/Vertexing• (π / K Separation)
CDF
DØ
Data Samples>2.5 fb-1 delivered>2 fb-1 recorded
Resultsupto Jan 6, 2007
CDF and DØ
RunII IntegratedLuminosity
04/19/02 -03/04/07
-
March 10-18, 2007 Alberto Sánchez-Hernández XLII Moriond EW 4
•c, b Hadron masses•c, b Hadron lifetimes•c, b Hadron decays
Tests ofinputs toHQE, CKM
Extractionof CKMparameters
• HQE: no leading order corrections a 1/mQGeneral feature of QCD gauge structure
• Precise prediction possible:
• Verification tests, validate of HQE
Why Lifetimes?
-
March 10-18, 2007 Alberto Sánchez-Hernández XLII Moriond EW 5
Measuring the lifetime
B
l+
l -J/ψ
h
!
ct = LxyB"MB /pT
Lxy
Proper decay time
decay length
Pros: Full recoCons: low stat
-
March 10-18, 2007 Alberto Sánchez-Hernández XLII Moriond EW 6
Measuring the lifetime
!
ct = LxyB"MB /pT
Proper decay time
decay length
B
l+ ν
D
Pros: large statCons: boost ambiguities,
K-factor needed
Boost correction
pT approx.
-
March 10-18, 2007 Alberto Sánchez-Hernández XLII Moriond EW 7
Bs Semileptonic Lifetime
• Flavor specific; Bs→µ+, anti-Bs→µ-• Fit effective lifetime distribution, τfs
!
"fs (WA) = 1/#fs
#fs = # s $ %# s( )2
/2# s + & %# s( )3
/# s2
# s = #L + #H( ) /2
psBsfs028.0
025.0044.0398.1)(+
!±="
PRL 97, 241801 (2006)
Mos
t pre
cise
mea
sure
men
t
world best!
DØ
DØ
-
March 10-18, 2007 Alberto Sánchez-Hernández XLII Moriond EW 8
More flavor specific B Lifetimes
Using µ and e lepton channelsin the flavor specific Bs decay:
Bs0 → l- ν Ds+ X
!
"(Bs) = 1.60 ± 0.10 ± 0.02ps
!
"(Bs) = 1.381± 0.055#0.046
+0.052 ps
Using a full-reconstructed decay channelsCDF
-
March 10-18, 2007 Alberto Sánchez-Hernández XLII Moriond EW 9
B LifetimesNew B → J/ψ X lifetime measurements
!
"(Bs) = 1.494 ± 0.054 ± 0.009ps
!
"(B0) = 1.524 ± 0.030 ± 0.011ps
!
"(B0) = 1.572± 0.025± 0.012ps
!
"(B+) = 1.630 ± 0.016 ± 0.011ps
uncertainties dominated by statistics, systematics < 1% level
CDF
!
Bs " J/#$
!
B0 " J/#Ks
0
!
B0 " J/#K0*
!
B+ " J/#K +
-
March 10-18, 2007 Alberto Sánchez-Hernández XLII Moriond EW 10
Λb Lifetimes
!
"(#b) = 1.580 ± 0.077 ± 0.012 ps
!
"(#b) = 1.298 ± 0.137 ± 0.050 ps
!
"(#b) = 1.28$0.11
+0.12± 0.09 ps
Due to the large background the#signal-event/cτ bin is used
1.3 fb-1
1.0 fb-1
DØ
DØ
CDF
!
"b # J/$"0
!
"b # J/$"0
!
"b# "
cµ$
-
March 10-18, 2007 Alberto Sánchez-Hernández XLII Moriond EW 11
03: 1.085 ± 0.01706: 1.076 ± 0.008
NLOTheory
03: 0.951 ± 0.03806: 0.957 ± 0.027
HFAG 2003HFAG 2006 03: 0.786 ± 0.034
06: 0.813 ± 0.030
C.Tarantino, hep-ex/0310241 and hep-ex/0702235
B Lifetimes summary
Significantimprovement overthe last years
-
March 10-18, 2007 Alberto Sánchez-Hernández XLII Moriond EW 12
1) CDF: Bs / B0 → h+ h’-– test of SU(3)– CP Asymmetries (γ)
2) CDF: Bs → Ds π+ & Ds 3π±– test of SU(3)
3) CDF: Bs → ψ(2S) φ– comp to B+,0 → ψ(2S) K+,*0
– CP-even vs -odd (c.f. Bs → J/ψ φ)
4) CDF: Bs → φ φ– CP-even vs -odd (c.f. Bs → J/ψ φ)
Fit for comp.● M (h+h–)● dE / dx● P(h+), P(h–)
Decay Modes● Ds
–(φπ–) π+● Ds
–(φπ–, K*0K–, π–π–π+) π+ π+ π–
CDF: 355 pb-1
Rare Hadronic B.R.s
CDF
-
March 10-18, 2007 Alberto Sánchez-Hernández XLII Moriond EW 13
CDF Branching Ratio Results
Colangelo, Ferrandes, PLB 627 (2005)
B(Bs→K+K–) ~ B(B0→K+π–) Buras, et al, NPB 697 (2004)
Williamson, et al, PRD 74 (2006)
= B(B0→ψ(2S)φ) / B(B0→J/ψφ)
Chen, et al, PRD 59 (1999)
Li, et al, PRD 68 (2003)
N(signal) Result Sigf
494±28 1.13 ± 0.08 ± 0.23
309±26 1.05 ± 0.10 ± 0.22
1307±64 2.44 ± 0.14 ± 0.46
230±38 5.00 ± 0.75 ± 1.00
26±21 < 1.36 @ 90% CL
32.5±6.5 0.52 ± 0.13 ± 0.07 6.4σ
7.3±2.9 1.4 ± 0.6 ± 0.6 4.7σ
prel
imin
ary
BR (scaled)
Hadronic BR Results
!
Bs"D
s
#$ +
B0"D
#$ +
!
Bs"D
s
#$ +$ +$#
B0"D
#$ +$ +$#
!
Bs" K
+K
# (x105)
!
Bs" K
#$ + (x106)
!
Bs" #$# + (x106)
!
Bs"#(2s) $
Bs" J/# $
!
Bs" ## (x105)
CDF
-
March 10-18, 2007 Alberto Sánchez-Hernández XLII Moriond EW 14
B → µ+µ– Predictions
● BR(Bs) = (3.4 ± 0.5) x 10-9● BR(B0) ↓ |Vtd / Vts|2 ~ 0.04
● BR ∝ tan6 β in MSSM ∝ tan4 β in 2HDM
Meeting the Experimental Challenges• Cut around J/ψ and ψ'• Discrim against other di-sources
– Isolation– Decay Length Significance– Angle b/w decay length and
momentum vectors• Normalize to known decays
– B+ → J/ψ K+
Leptonic Bs Decays and FCNCs
d ,s
u ,c ,t
W
W
d ,s
t
H
W
µ+
µ-
µ-
µ+
ν
ν
!
b
!
b
B
B
-
March 10-18, 2007 Alberto Sánchez-Hernández XLII Moriond EW 15
DØ new result on B → µ+ µ– using 2fb-1 of data
Preliminary FCNC Results
!
LHR =
Si(x)
i=1
6
"
Si(x) + B
i(x)
i=1
6
"i=1
6
"
Using a revisited selectionmethod based on a likelihoodratio
DØ
90%CL 7.5 x 10-8 (DØ combined)
RunIIa
RunIIb
-
March 10-18, 2007 Alberto Sánchez-Hernández XLII Moriond EW 16
B → µ+ µ– Results
Summary Exp Mode Lumi [fb-1] Evts Bgrd Pred BR Limit (95% CL) DØ Bs → µ+ µ– 2 3 2.3 ± 0.5 < 0.93 x 10-7 CDF Bs → µ+ µ– 0.78 1 1.27 ± 0.37 < 1.0 x 10-7 Bd → µ+ µ– 0.78 2 2.45 ± 0.40 < 0.3 x 10-7
Preliminary FCNC Results 2
CDF
!
Br(Bs) limit
Br (Bs) SM
" 20
!
Br(Bd) limit
Br (Bd) SM
" 300
-
March 10-18, 2007 Alberto Sánchez-Hernández XLII Moriond EW 17
Lifetimes Very significat improvement over the last year Getting best measurements on Bs and Λb (had and SL) B+ and B0 competitive to B-factories
Hadronic rare decays– Important test for SU(3)
Leptonic rare decays– New 2fb-1 result from DØ– A factor of ~20 of SM µ+µ– prediction
DØ: improving analysistechniques and accessingdata as available
Summary and Prospects
RunII Integrated Luminosity [fb-1]
-
March 10-18, 2007 Alberto Sánchez-Hernández XLII Moriond EW 18
Backup
-
March 10-18, 2007 Alberto Sánchez-Hernández XLII Moriond EW 19
B Lifetimes summary
At the same levelas b-factories
C.Tarantino, hep-ex/0310241 and hep-ex/0702235
03: 1.085 ± 0.01706: 1.076 ± 0.008
NLOTheory
03: 0.951 ± 0.03806: 0.957 ± 0.027
HFAG 2003HFAG 2006 03: 0.786 ± 0.034
06: 0.813 ± 0.030
see also C.Tarantino, hep-ex/0702235
-
March 10-18, 2007 Alberto Sánchez-Hernández XLII Moriond EW 20
DØ new result on B → µ+ µ– using 2fb-1 of data
Preliminary FCNC Results
!